1. Field of the Invention
The present invention relates to a portable electronic device with switchable operation modes and an operation mode switching method thereof and, more particularly, to a portable electronic device with an operation mode determined in accordance with power consumption and an operation mode switching method thereof.
2. Description of Related Art
With the continued progress of science and technology and the development of the communication and consumer electronic industries, electronic devices with many kinds of functions are more and more appreciated. For instance, many of today's mobile phones have a built-in digital still camera (DSC) function, or a mobile phone function is often added into personal digital assistants (PDAs). A single device can thus become multifunctional. In addition to achieving more plentiful activities, more added values can also be generated to increase the market share of a device.
In order to make a single device multifunctional, however, there inevitably are drawbacks in quality. For example, the picture quality of the DSC function of today's mobile phones is inferior to that of more specialized cameras. For improving the picture quality of the DSC function in a mobile phone and increasing the number of pixels of the DSC module, the mobile phone system and the DSC module can be separately used with current techniques so that the DSC module can perform image processing and operations using its own processor. The DSC module then, is no longer limited by the image processing capability of the processor of the mobile phone system. The DSC function in the mobile phone can therefore be enhanced to the level of mainstream DSCs in the market.
However, the problem of power consumption arises. For instance, a mobile phone with a DSC function consumes more power during its operation than a simple mobile phone. FIG. 1 is a diagram showing the reference capacity point of the prior art, wherein the power-off capacity point of the mobile phone system and that of the DSC module are set to the same capacity point T. This will lead to the problem of the mobile phone system shutting off once the DSC module is shut off. Therefore, the mobile phone cannot fully utilize its battery power, and its standby time is short.